The invention discloses a mapping method for drawing a nuclear power plant terminating map. The mapping method comprises the steps of S1, importing preset terminating data into a mapping system, S2, selecting cables and apparatuses in the mapping system and then establishing a logical connection relationship between the apparatuses by virtue of connection of the cables, S3, after allowing the preset number of terminals for the apparatuses, automatically distributing the terminals of a control cabinet according to the preset terminating data and establishing a logical connection relationship between the terminals of the cables and the apparatuses and the terminals of the control cabinet, S4, completing the drawing of the minimum unit map of the nuclear power terminating map, and S5, automatically copying the minimum unit map and completing the drawing the the nuclear power terminating map. The invention also provides a mapping system for drawing the nuclear power plant terminating map, and the mapping system is used for implementing the method. The mapping method and the mapping system for drawing the nuclear power plant terminating map are quick in mapping and high in accuracy.